In Did You Know? the National Geographic magazine team shares extra information we gathered to expand your knowledge of our featured subjects.

The Northwestern Hawaiian Islands harbor more than just beautiful and unique plants and animals. "There are some 60 ships known lost in the Northwestern Hawaiian Islands area, as well as at least 67 aircraft," says NOAA's maritime heritage coordinator Hans Van Tilburg. Designating the area a national marine sanctuary would mean additional protection and possibly more in-depth research into these important cultural finds. Working with the U.S. Fish and Wildlife Service and the State of Hawaii, Van Tilburg's group of nautical archaeologists began studying the wrecks along the archipelago in 2002, and earlier this year conducted surveys in hopes of confirming the identity of specific ships. Their maritime fieldwork has involved such interesting finds as two whalers at Pearl and Hermes Atoll, thought to be the wrecks of two British ships of the same name that went down in 1822, and for which the atoll is named. "Sanctuary designation," notes Van Tilburg, "brings with it a recognition of maritime heritage and cultural resources, as well as the conservation and protection of our fragile coral reef ecosystems."